Telephone system.



E. E. KLHNSCHMIDT. TELEPHONE SYSTEM. APPLICATION FILED FEB. 25 1910| 1 J8? Patented May 4, 1915.

5 $HEETS-SHEET I- E. E! KLEINSCHMIDT.-

TELEPHONE SYSTEM.

APPLICATION mu) FEB. 25. I910.

Patented May4,1915.

Mama

5 SHEETS-SHEET 2.

E. E. KLEINSCHMIDT.

TELEPHONE SYSTEM.

APPLlCATlO'. FILED FEB. 25. 1910.

Patented May 4, 1915;

5 SHEETSSHEET 3.

ATTORNEY E. E. KLEINSCHMIDT.

TELEPHONE SYSTEM.

APPLICATION FILED FEB. 25. 1910.

Patented May 4, 1915.

5 SHEETS-SHEET 4.

VMNESSES:

INVENTOR E. E. KLEINSCHIVIIDT. TELEPHONE SYSTEM.

APPLICATION FILED FEB. 25. 1910.

1 13 65., Patented May 4, 1915.

I "EDWARD E. KLEINSCHMIDT,

MENTS, T HALL SWITCH & SIGNAL 0 OF NEW Y ORK, N. Y., ASSIGNOR, BY MESNE ASSIGN- OMPiltNY, A. CORPORATION OF MAINE.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented May t, 1915.

To all whom it may concern:

Be it known that I, EDWARD E. KLEIN- SCHMIDT, a citizen of the United States, residing at New York city, borough of-Manhattan, in the county of New York and State of- New York; have invented certain new and useful Improvements Telephone Systerns, of which the following 1s a specification. r I

My invention relates to new and useful improvements in telephone systems of that character or type including a mam circuit upon which is bridged a plurality of local stations and provided with selective signaling apparatus whereby a call operator may selectively signal the desired local station independently of the others on the line. The invention relates more particularly to the signaling system employed for selectively signaling the local statlons, and the purpose of the invention is to provide means whereby the despatcher, monitor or call operator in charge of the circuit may quickly call any station along the line independently of the others; also to provide means by which a time signal may be automatically sent to the several stations.

The invention particularly contemplates the provision of novel and improved means whereby a commercial system such as is generally in use by railroads may have bridged thereon a signaling circuit in addition to the usual calling means, by means of which additional signaling circuit a local station may be signaled by a train despatcher or other central station without the necessity of calling through the usual central which controls the main circuitor commercial line.

Generally stated, the system comprises a plurality of auxiliary signaling stations bridged onto the line, and a sending or call station located at the despatchers or monitors ofiice, together with a main circuit which may be used for telephonic communication. The signaling devices and the local stations in connection with which they are employed are bridged on the main circuit,

the signaling devices being made ofsufficiently hi h impedence to prevent their short-circulting the talking circuit.

The invention will be understood by reference to the accompanying drawings in which- Figure 1 is a diagrammatic View of a complete system. Fig. 2 is a face view of the sending machine, the front plate partly broken away. Fig. 8 is a section through the sending machine on line 33 of Fig. 2. Fig. 4 is a side View of part of the sending machine showing the commutator and the stopping device. Fig. 5 is a detail view of the stopping device. Fig. 6 is a detail view of the commutator. Fig. 7 is a detail view of the push rod in the sending machine. Fig. 8 is a face view of the selector. Fig. 9 is a side view of the selector with the casing broken away. Fig. 10 is a sectional view of the selector along the line 10 looking in the direction of the arrows. Fig. 11 is a sectional view of the selector on line 11 looking in the direction of the arrows. Fig. 12 is a detail View of the selector showing the ratchet wheel and the mechanism for operating it. Fig. 13 is a view of the ratchet wheel showing dotted the stop and spring beneath it.

Referring to Fig. l of the drawings, 11 designate the conductors of a main line circuit and 22 are local stations bridged onto said circuit, said local stations each including a transmitter 3 and receiver 4 which may be of any construction employed in such apparatus. I wish it understood that the specific construction of the receiving and transmitting apparatus at the local stations forms no part of my invention, and it is, therefore, unnecessary for me to make a detailed description of the same.

Bridged onto the main line circuit is a signaling circuit by means of which the call operator may selectively signal the desired subscriber station. In the drawings I have shown one of such signaling circuits applied to each of the local stations shown, but I desire it understood that one of such systems could be employed for signaling a plurality of subscriber stations, should it be so desired. This signaling circuit, or system, includes a pair of selector magnets 5, 5 bridged onto the main line by a metallic circuit 6, 6 which circuit may include an adjustable resistance T, if desired. The magnets 5, 5 are constructed so as to have sufficient impedance to prevent the talking circuit being short-circuited through them, and the resistance 7 may be constructed inductively in whole or in part so as to thereby increase the resistance of the signaling circuit to the talking current.

Cooperating with the cores of the magnets 5, 5 is a polarized armature 8 preferably fulcrumed intermediate its ends, as at 9, so that said armature will rock on its pivot or fulcrum when influenced by said magnets 5, 5. hese magnets 5, 5 constitute a selector by means of which the individual selecting and signaling apparatus for each local station is controlled and operated, the selecting and signaling apparatus being controlled by the movements of said armature 8. Carried by this armature and operated thereby is a pivoted pawl 10 normally held in the position shown in Figs. 8 and 12 by a spring 11, said pawl having a projection 12 cooperating with a stop pin 13 on the armature by means of which the pivotal motion of said pawl in one direction is limited. This pawl is also provided with a heel por tion 14 to serve a purpose to be presently set forth. The pawl 10 cooperates with the teeth of a ratchet wheel 15 constituting a contact carrier or mover, and which is revolubly mounted on one end of an intermediately fulcruzned lever 16, said lever carrying, at the end 0 posite to that upon which the ratchet wheel is mounted, an armature 17 which cooperates with what might be termed a resetting magnet 18, said resetting magnet being arranged in a circuit including the conductors 19 and 20 which circuit is controlled by the operation of the polarized armature 8 to energize .or denergize the resetting magnet by current furnished from the calling station and transmitted .over the main line, said calling apparatus being independent of that usually employed on the commercial circuit. The conductor terminates in a contact 21 arranged adjacent the armature 8 so as to be engaged by the latter when a current of determined polarity is sent through the magnets 5, and the conductor 20 is electrically connected to the lead 6 of the selector magnet circuit, the arrangement being such that the said resetting magnet is energized by means of the armature 8 engaging the contact 21, the complete circuit for the resettin magnet being included by the lead 6 of the selector magnet circuit, the conductors '19 and 20, the contact 21, the polarized armature 8, and a conductor 22 connecting the polarized armature with the other limb 6 of the selector magnet circuit. Itwill thus be seen that in the event the magnets 5, 5 are ener-v gized by current of proper polarity to rock the armature so as to place the same in contact with the contact 21-that the circuit for the resetting magnet will be energized, and the resetting magnet will attract the armature 17 which will serve to swing the lever 16 on its fulcrum and thereby move the ratchet wheel out of engagement with the pawl 10. A spring actuated pawl 15 may be employed to prevent reverse movement of the ratchet wheel 15 if so desired. This pawl, when the lever is rocked on its fulcrum to release the wheel from its pawl 10, strikes a projection 15 in the casing which moves said pawl 15*.out of engagement with the wheel.

The ratchet wheel above referred to has adjustably mounted thereon a contact 23 adjustable about the face of said ratchet wheel for a purpose to be presently set forth, a binding screw 23 being employed to hold the contact in adjusted position. Arranged adjacent the ratchet wheel and in' the path of the contact 23 is a contact 24, the arrangement being such that when the ratchet wheel is rotated clock-wise the contact 23 may be brought into engagement with the contact 24. This contact 24 is connected moves said armature into engagement with i,

the contact 21. This arrangement is such that, should the contact 23 be brought into engagement with the contact 24, the magnet 29 is energized to operate any form of signal which it may be utilized to control. In the present embodiment the signal consists of a bell 32, the striker 33 of which is connected to the armature 28. It will be seen that the energization of the magnet 29 will vibrate the striker to sound the bell, the circuit being made and broken at the contacts 26, 27 to cause the vibration of the striker. The signaling apparatus may also include a visual signal, as for instance a pivoted drop34 having a tail piece 35 which is normallv engaged by the armature 28, the arrangement being such that when said armature is attracted by the magnet 29 it moves out of engagement with the tail of the drop and permits the latter to fall to signaling position.

The ratchet wheel15 is fixed to its shaft, and is connected to the lever 16 by means of a coil'spring 15 the ends of which respectively engage said shaft and lever, the function of said spring being to return the. ratchet wheel to its initial position whenever it is released from engagement with the pawl 10. It will be understood that the contact 23 is so connected to the ratchet wheel that any rotation of the ratchet wheel in. either direction will carry said contact with it, and that, therefore, the spring not only returns the ratchet wheel to initial position but also the contact.

menses Means is employed for impressing on the line currents of different characteristics one of which operates first to energize the magnets 5, 5 to close the circuit betweenthe contact 21 and the armature 8 and energize the magnet 18 to move the ratchet wheel 15 out of contact with the pawl 10 whereby the spring may operate to reset the contact 23. This having been accomplished another current-is impressed upon the line of a character which energizes the magnets 5, 5 to vibrate the armature 8, and subsequently impressing another impulse of another kind to-close the signaling circuit and ring the signaling bell. The means for accomplishing this result will now be described. Before describing in detail this means for impressing currents of different characteristics I would state that I do not desire to be limited to any particular kind or kinds of currents, but, as at present contemplated, I employ a direct current and utilize what I might term a long impulse of the proper polarity as the agent for at first energizing the magnets 5 to operate the polarized armature 8 to close the circuit of the'resetting magnet 18, and having accomplished theresetting operation I then employ a plurality of short reversals depending in number to the station to be called, which cause the vibration of the polarized armature to stepup the contact 23 to close the signaling circuit, and subsequently another long impulse is then em ployed for energizing the signaling circuit as above stated, said last impulse being of different polarity from the first long impulse.

Referring particularly to Figs. 2 to 7 of the drawings, 36 designatesa casing of a calling apparatus, containing a shaft 37 upon which is mounted a manually operable calling lever 38 by means of which the said shaft may be operated clock-wise, said shaft being rotated in the opposite direction by a spring 39 coiled about the shaft and having one end fixed to the shaft and the other to the casing as at 40. The calling lever cooperates with a dial 41 having a plurality of spaces 42 to receive indicia of the various stations on the circuit, and, upon being moved clockwise to take a position opposite one of these spaces, controls means upon its return movement under the influence of the spring 39 to impress upon the line a number of short reversals according to the station to be signaled. Loosely mounted upon the shaft 37 is a spur gear 43 and secured to one face of this spur gear is a ratchet disk 44. Fixed to the shaft is an arm 45 which is in alinement with the selector lever, and car-- ried by the arm 45 is a pawl 46 coeperating with the ratchet 44 to turn it and the gear 43 when the selector lever is moved counterclockwise.

The spur gear 43 is in mesh with a pinion 47 on the shaft 48 of a commutator 49, the said shaft being geared by gears 50, 51 to a governor shaft 52 carrying a ball governor 53 which regulates the speed of rotation of the commutator shaft. The commutator consists of two sleeves 54, 55 mounted on the commutator shaft and insulated therefrom,-

and divided by insulation blocks 56 into four sections. Brushes 57 are connected to the opposite poles of a battery 58, said brushes cooperating with the commutator on the spaces outside the blocks 56; in other Words, are always in circuit with the commutator. Also engaging the commutator are'pairs of brushes 59,60, the brushes of eachpair being connected together, the brushes 59 and 60 being connected by leads 61, 62 respectively withthe Wires of the telephone circuit, the lead 62 including a pair of spring contacts 63 which normally tend'to close to complete the circuit; These contacts form part of the calling mechanism, and are arranged to be normally separated=when the selector lever is in its initial position, the separating means consisting preferably of an insulating projection 64 carried by the arm 45 on the shaft 37. The arrangement is such that whenever the selector lever is in the position shown in full lines in Fig. 2 the battery 58 is disconnected from the line, but whenever the lever is moved to call a station the contacts are released to close the circuit to throw currentinto the line.

In signaling the selected station the lever is first moved to the position opposite the space on the face plate of the-calling mechanism corresponding to the station to be called, which throws a long impulse of direct current onto the line, this (long impulse being employed to energizethe magnets 5, 5 to actuate the armature 8 to close the circuit through the magnet 18 and thereby move the ratchet wheel 15 from engagement with the pawl 10 and permit said Wheel to be returned to initial position by the spring 15 The lever is then released to be moved toward its initial position by the spring 39 and this return movement carries the gearwheel 43 with it which rotates the commutator and sends over the line a plurality of short impulses of alternating polarity, the number of impulses being de terinined bv the extent of movement of said lever. These impulses of direct current of inside of the front wall of the casing and arranged to engage a stop face 66 on the arm 45 heretofore described, said arm having a cam face 67 to guide the end of the latch into engagement with the face 66. The latch is normally urged toward locking position by means of a spring 68, and is moved in the opposite direction to release the lever by means of a plunger 69 extending exteriorly of the casing and accessible to the operator. When the lever reaches the position where it is held by the latch 65, it does not separate the contacts but leaves the same closed so that along impulse of opposite polarity of the first longv impulse is impressed on the line to operate the signaling circuit. The signal having operated for a sufiicient length of time, the lever is released to again separate the contacts and cut out the signaling apparatus.

I will now proceed to describe the arrangement by means of which the signaling and selecting apparatus may be employed to send time signals over the line to the stations on the system.

Connected to the lines 61, 62 is a relay circuit 70 including a relay 71 and a switch 72, the latter being open during the normal operation of the system but adapted to be closed whenever it is desired to send time signals over the line. When the time signals are to be sent the lever 38 is moved clockwise to its extreme position, which at first releases the contacts 63 and causes the magnets 5, 5 and 18 to be energized to reset the ratchet wheel 15, the latter being re-' turned to its extreme position, its movement in this direction being limited by a projection 15 thereon engaging a stop 15 on the lever 16. The return movement of the lever sends a number of impulses over the line sufiicient to step up. the ratchet wheel until it brings a contact 72 thereon into engagement with a spring contact 74: which is connected by a conductor 75 directly with the signaling magnet 29L When the selectors have been set the lever 38 is permitted to assume its normal position to separate the contacts 63, and the switch 72 in the relay circuit is closed to bridge the relay into the line. The current which is of difierent polarity from that of the originallong impulse used to reset the ratchet, energizes the magnets 5 to move the armature 8 to the position shown in Fig. 1, making contact with the terminal 26 connected by the conductor 26 with the lever 16. The complete timing circuit is from the main battery 58 by way of one of the brushes 60, contacts of switch 72, contacts of relay 71 and lead 62 to the main line, thence by the lead 6 through the magnets 5, and also through the wires 22, armature 8, contact 26 and conductor 26*, lever 16, contacts 73, 74, conductor 75, to the signaling magnet and back by conductor 31 to the other branch of themain line to the lead 61, to one of the brushes 59, to battery. By this arrangement whenever an impulse is sent through the relay 71 the relay lever is opened and closed to send an impulse over magnet 29 to sound the bell, the connections being such that a single stroke'of the bell is produced. Bridged onto the circuit 25 is a local clock circuit 76 including a push-button switch 77 which, at the proper time, is closed by the operator to set the clock in accordance with the timing circuit. The time signals having been completed, the switch 72 is operated to again open the relay circuit and the timing circuit is thereby disconnected from the signaling circuit.

Between the line and battery are connected retardation coils 80, their respective terminals on the battery side being connected together through a condenser, the purpose of this arrangement being to cause the impulses which are impressed on the line to rise and fall very gradually so that the noise created thereby on the telephone receivers be reduced to a minimum.

1 have referred to the operation of the several parts of the invention during the progress of the above description but deem it advisable to state the operation of the complete apparatus as follows :-When the operator at the calling station desires to signal one of the local stations on the main line he grasps the lever 38 on the calling apparatus and moves the same clockwise. The initial movement of this lever removes the projection 64: from between the contacts 63, which engage to complete the circuit connecting the battery 58 with the main line.

The commutator controlled by the actuation of the lever 38 is in'position to send a long impulse of direct current over the main line, which current is established as long as the lever is out of engagement with the contacts and during its movement clockwise. The closing of the contacts 63 causes the selector magnets 5, 5 to be energized, the current flowing from the battery 58 by way of one of the brushes 57, the commutator, one of the brushes 59, and one limb of the circuit 61, 62 onto the main line, thence over the main line to one of the limbs of the circuit 6 through the magnets, and by way of the other limb of the circuit 6 onto the other lead of the main line, back through the controlling circuit and the brushes 59, 57 to the battery. As above stated, this serves to energize the magnets 5 which moves the polarized armature 8 toward the right, as shown inFig. 1, closing the contact at 21 and completing the circuit including the lines 19 and 20 through the resetting magnets 18, the complete circuit being one of the leads of the circuit 6, the conductor 22, the armature 8, conductor 19, to the magnet 70 the signaling circuit and this energizes the 18, and thence by way of the conductor 20 to the other lead on the circuit 6 through the adjustable resistance back to the main line. The energization of the magnet 18 serves to throw the ratchet wheel 15 out of engagement with the pawl 10, whereby the spring connecting the ratchet wheel with the lever 16 automatically returns the ratchet wheel to its initial position, carrying with it the contact 23. All of the operation just referred to is caused by the move ment of the lever 38 clockwise. This lever having been moved to take a position opposite one of the spaces 42 allotted to the station which it is desired to call, is releasedby the operator and is returned by the spring 39 to the position shown in dotted lines in Fig. 2, in which position said lever is held by the latch 65. During this return movement of the lever the pawl 46 engages with the ratchet wheel 44, turnthe same counter-clockwise and carrying ing with it the gear 43. This movement of the gear 13 serves to rotate the commutator which impresses upon of short impulses of alternating polarity. This current traverses the circuits 61, 62, the main line and the circuit 6, to energize the magnets 5, 5, the latter vibrating the polarized armature 8 to cause the pawl 10 thereon to engage the ratchet wheel to step the same forwardly and thereby bring the contact 23 into engagement with the contact 24. During this operation of the polarized armature the circuit 19, 20 through the magnet 18 will of course be closed at the contact 21, but the engagement of the contact is of so short duration that the magnet 18 is not energized to withdraw the ratchet wheel from engagement with the pawl 10.

The contact 23 being moved into engage-.

ment with the contact 24, the rotation of the ratchet wheel ceases for the reason that the extent of movement of the lever 38 is determined so as to send out over the line a number of short impulses which is just suilicient to step the contact 23 into engagement with the contact and upon said lever reaching the position shown in dotted lines in Fig. 2, the rotation oi? the commutator ceases and the commutator is left in position to send over the line a long impulse of direct current of constant polarity, but of opposite polarity from that sent over when the lever 38 is first moved out of engagement with the contact 63.. When the contacts 23 and 2& are in engagement the circuit through the signaling magnet 29 is closed, said circuit being from the battery 58 by way of one of the brushes 57, the commutator, and one of the brushes 59 to the main line, thence over one of the leads of the circuit 6, the conductor 22, the armature 8, the contact 26* and conductor 26 to the lever 16, thence through the contacts 23, 2d

the line a plurality and conductor 25 to the contacts 26, 27, the conductor 30, through the magnet 29, and thence by the conductor 31 to some point on the adjustable resistance 7. I desire to connect the conductor 31 to the adjustable resistance in order that the current through the magnet 29 may be regulated so that it will always be sufficient to rock the armature 28 to ring the bell 32. The signal having been given the operator at the calling station operates the push-button 69 to release the latch from engagement with the lever 38, whereby the spring 39 returns said lever to its initial position with the insulatedprojection 64 between the spring contact 63, breaking the circuit between the battery 58 and the main line. This movement of the lever also serves to further rotate the armature so that the latter will be brought to the same position it held before the calling operation takes place.

' it will be understood that the final long impulse of direct current is of the proper polarity, so that when the magnets 5, 5 are energized the armature 8 will be moved to the left, to the position shown in Fig. l, to close the signaling circuit by means of the contact 26".

When it is desired to send the time-signal over the line the circuit 7 0 is closed by moving the lever 72 downward, and the lever 38 is then moved to its farthest position clockwise and released, the spring returning it toward its first position. This operation serves to energize all of the magnets 5, 5 which may be on the line, at the several local stations and to energize the magnet 18 to reset the ratchet wheels 15, this operation serving to bring the contact 73 on the ratchet wheel in engagement with the spring contact 74, thereby closing the circuit through the magnet 29. It will thus be seen that whenever an impulse is put on the line from the magnet or relay 71 that the magnet 29 will be energized to give a single stroke to the bell 32. At the proper time during the giving of the time-signal at the local station the operator closes the local circuit 76 by means of the push-button switch 77, so that when the final impulse is sent through the magnet 29 from the relay 71 the electric setting mechanism in the clock will set the hands at the proper time, say, for instance, twelve oclock. The time-signal having been completed the lever 72 is raised to again separate the contacts controlling the circuit 70. During the signaling operation when the magnet 29 is energized the drop 3% is released to close contacts controlling a local ringing circuit 79, this circuit serving to continuously give a signal after the circuit through the magnet 29 is broken. The circuit through the local circuit can be broken by resetting the drop by means of a thrust rod 80 shown in Fig. 1 of the drawings.

What I desire to claim ters Patent is:

1. In a system of the character described, a calling station and a plurality of local stations connected by aline circuit, selective switches included in branch circuits bridged on theline circuit at the local stations, means for impressing reversals of the current on the line circuit and for impressing a direct current on the line circuit, means responsive to the said reversals and to said direct current, respectively, for setting said switches, and for resetting said switches to normal position.

2. In a system of the character described, a calling station and a plurality of local stations connected by a line circuit, selective switches bridged on the line circuit at the local stations, means for impressing direct current impulses of opposite polarity on the line circuit, means responsive to the direct current impulses for restoring the switches to normal position and for setting the switches according to the polarity of the impulses, and a signal included in a branch circuit which is bridged on the line circuit when the corresponding selective switch is set, whereby said signal will be operated by the direct current on the line of. reverse polarity to that for restoring the switches.

3. In a system of the character described, a main circuit, a signaling circuit bridged onto the main circuit, a circuit closer for closing the signaling circuit, resetting means for the circuit closer, a selector magnet, a polarized armature-influenced by said magnet, said polarized armature operating to actuate the resetting means and then close and secure by Letthe signal circuit closer, and means for suc-.

cessively passing through said controller magnet an impulse of direct current and subsequently a plurality of impulses of alternating polarity.

4. In a system. of the character described, a main circuit, a signaling circuit, a circuit closer controlling the signaling circuit, resetting means for the circuit closer, a circuit including the resetting means, step by step mechanism for setting said circuit 50 closer, a magnet, a polarized armature influenced by said magnet'for operating the step by step mechanism and closing the resetting circuit, and means for sending a direct current impulse through said magnet to control the resetting circuit and subsequently sending a plurality of impulses of alternating polarity through said magnet to operate the step by step mechanism.

5. In a system of the character described, a main circuit, a selecting circuit bridged onto the main circuit, a magnet in the selecting circuit, a polarized armature influenced by said magnet, a circuit including a signal, a circuit closer for closing the signal circuit operated by a current of alternating polarity through the polarized armature, resetting means for the circuit closer, and means whereby a current of given polarity sent through said magnet will close the resetting circuit the signaling circuit being subsequently closed by alternating impulses.

6. In a system of the character described, a main circuit, a selecting'circuit bridged thereon, a selector magnet in said circuit, a polarized armature cooperating with the magnet, a signal circuit, a circuit closer operated by the magnet for closing the signal circuit, a circuit including resetting means for the circuit closer, means for sending a plurality of short reversals of current through said magnet to vibrate the armature to actuate the circuit closer, and for sendinging a current of constant polarity through said magnet to close the circuit for the resetting means.

7. In a system of the character described, a main line, a signaling circuit including a signal actuating magnet, a step by step circuit closer for closing the signaling circuit, a circuit including a magnet acting to reset the circuit closer, a'polarized armature for closing said circuits, according to the polarity of the current and for actuating the circuit closer, a magnet influencing the armature and in circuit with the main line, and means for sending through said magnet a direct current of given polarity to cause the armature to first close the circuit for the resetting means, then a series of short reversals to operate the step by step mechanism to close the signaling circuit and subsequently a long impulse of direct current of opposite polarity from the first-mentioned long impulse to cause the armature to complete the signaling circuit.

8. In a system of the character described, a main circuit, a circuit bridged thereon including a selector magnet, a signal circuit, a step by step circuit closer including a ratchet for closing the signal circuit, actu- ,ating means controlled by the magnet for stepping the ratchet to close the circuit closer, and means under the influence of said magnet for moving the ratchet out of engagement with the ratchet stepping means. 9. In a system of the class described, a main circuit, a circuit including a selector magnet bridged thereon, a signal circuit, a step by step circuit closer including a ratchet for closing the signal circuit, a pawl operated by the magnet, and means controlled by the magnet for moving the ratchet out of engagement with the pawl to permit resetting of the ratchet.

10. In a system of the class described, a main circuit, a circuit including a selector magnet bridged thereon, a signal circuit, a step by step circuit closer including a ratchet for closing the signal circuit, a pawl operated by the magnet, a magnet for moving the ratchet out of engagement with the pawl to permit resetting of the ratchet to open the circuit closer, and means under the influence of the selector magnet for controlling the circuit through the resetting magnet.

11. In a system of the character described, a line circuit, a signaling mechanism bridged thereon responsive to currents of different characteristics, said mechanism including a switch and means for setting and restoring the same responsive to impulses of a given polarity and then to impulses of alternating polarity for restoring and setting respectively, and a signal bridged across the line by said switch and responsive to direct current, a source of direct current bridged onto the line circuit, a calling mechanism associated with the source of current for first sending a direct current impulse over the line to restore said switch to normal, and then a plurality of impulses of alternating polarity to set said switch, and subsequently a direct current impulse to operate the signal,

12. In a system of the character described, a main circuit, a signaling circuit bridged thereon, a signal setting and resetting means responsive to current of alternating polarity and to direct current for setting and resetting respectively, a source of current in an open circuit bridged onto the main line, a commutator in said circuit rotatable to send a plurality of impulses of alternating polarity over the main circuit onto the" signaling circuit, and means for determining the number of rotations of the commutator to regulate the number of alternating impulses impressed on the line.

13. In a system of the character described,

a main circuit, a signaling circuit bridged thereon, a signal setting and resetting means responsive to current of alternating polarity and to direct current for setting and resetting, respectively, a source of current in an open circuit bridged onto the main line, a commutator in said circuit rotatable to send a plurality of impulses of alternating polarity over the main circuit onto the signaling circuit, means for rotating the commutator, and means for setting the rotating means to determine the number of rotations of the commutator so as to regulate the number of alternating impulses impressed on the line.

14. In a system of the character described, a main circuit, a signaling circuit bridged onto the main circuit including a signal, a step by step circuit closer for closing the signal circuit, a magnet operable under the influence of a plurality of impulses of alternating polarity to step the circuit closer, resetting means for the closer responsive to direct current in said magnet, a source of current bridged onto the main line, and manually operable means for impressing on the line impulses of direct current and a plurality of impulses of current of alternating polarity.

15. In a system of the character described,

a main circuit including local stations, a signal circuit at each local station bridged onto,

the main circuit and including an adjustable circuit closer, step by step means including a polarized armature for operating the circuit closer to close the circuit through the signal, a controlling magnet acting on the armature operating the step by step means, resetting means for the step by step means, a magnet and circuit' for operating the resetting means, and means whereby a direct current through the controlling magnet closes the resetting circuit, a plurality of reversals then influencing the polarized armature to step the step by step means.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EDWARD E. KLEINSCHMIDT.

IVitnesses:

M. E. MGNINCH, C. G. HEYBURN. 

